The present invention relates generally to a passive ossicle prosthesis comprising an applicator. More particularly, the present invention relates to an ossicle prosthesis that replaces or bridges at least one component of the human ossicular chain, in the case of which the ossicle prosthesis includes, at one end, a first fastening element for mechanical connection to the tympanic membrane or a component of the ossicular chain, in particular to the limb of incus or the manubrium of malleus, and, at the other end, includes a second fastening element for mechanical connection to a further component or parts of a component of the ossicular chain, or directly to the inner ear, and including an elongated connecting element that connects the two fastening elements in a sound-conducting manner.
A passive ossicle prosthesis of this type is made known, e.g., in DE 20 2007 012 217 U1.
Ossicle prostheses of this type are used to improve sound transmission in patients having different pathologies. They are used to conduct sound from the tympanic membrane to the inner ear in cases in which the ossicles of the human middle ear are missing or damaged, either entirely or partially. The ossicle prosthesis has two ends; depending on the specific circumstances, one end of the ossicle prosthesis is fastened to the tympanic membrane, e.g., using a top plate, and the other end of the ossicle prosthesis is fastened, e.g., to the stapes of the human ossicular chain, or it is inserted directly into the inner ear.
Three types of ossicle prostheses used particularly frequently are stapes prostheses, partial prostheses, and total prostheses. Stapes prostheses are fixed to the incus or the manubrium of malleus, and extend via a piston into the inner ear. Partial prostheses typically bear via a top plate against the tympanic membrane and establish a connection to the head of the stapes. Total prostheses connect the tympanic membrane to the base of the stapes.
The maximum length of implantable, passive ossicle prostheses of this type is on the order of only a few millimeters, which makes practical handling of the prostheses difficult. For surgical implantation in the human middle ear, surgeons typically use a microscope as well as suitable special instruments such as pincers, tweezers, fine needles, microsuction devices, and the like.
U.S. Pat. No. 6,892,466 B2 describes a special applicator designed to insert mock-ups of prostheses into the middle ear in order to determine the actual size of an individual ossicle prosthesis required for a particular patient. Since the prosthesis mock-ups described therein should match the ossicle prostheses to be used as closely as possible in terms of shape and size, an applicator of this type would also be suitable for use, of course, to insert the actual prostheses.
However, the disadvantage of the use of these known applicators is that they must be thoroughly disinfected and sterilized before the surgery takes place, as is the case for every other surgical instrument. Furthermore, these applicators are typically not specially matched in terms of shape and size to the ossicle prosthesis current being used, and so several different applicators must be made available in advance if the aim is to ensure that a certain prosthesis may be selected from the rather large assortment that is available. Otherwise the surgeon must quickly decide, during surgery, which of the available applicators he wants to use to handle the prosthesis selected on an ad hoc basis to be inserted into the middle ear of the patient; this approach often results in a less-than-optimal selection of the tool and, therefore, to a further complication of the implantation operation which is not trivial to start with.
This may result in a further, even more serious problem: Since the dimensions involved are so small, surgery in the middle ear must take place under the microscope. During the first stage, the microscope is directed by the operating surgeon onto the surgical site, i.e., the auditory meatus or the middle ear. When the point is reached during surgery at which the ossicle prosthesis should be inserted, the microscope usually remains sharply focused on the region of the middle ear observed most recently, of course, while the prosthesis is removed from its sterile packaging in which it is stored and shipped. For this purpose, most operating surgeons use an instrument which has typically not been optimized for this application, nor do they use the microscope which has been focused on the surgical site; instead, they reach, in particular, for the prosthesis, without magnification, and “by feel and using the naked eye”. In so doing, the ossicle prosthesis often becomes damaged or is even destroyed, thereby making it necessary to insert another implant in the region of the auditory meatus or the middle ear.
However, reaching for and handling a device as small as an ossicle prosthesis and, in particular, placing it and orienting it in exactly the proper place in the middle ear should be carried out using the finest precision possible, and, mainly, in a routine, standardized manner.